In the prior art, for the storage of beverages that have their taste deteriorated by oxidation, such as wine, sake, whiskey, fruit beverages, and vegetable juices, glass bottles have been used which are sealed with large-sized cork stoppers or screw caps. However, these glass bottles are heavy and brittle so that they are seriously troublesome to handle. It is, therefore, the current practice to use PET bottles made of plastic in place of the glass bottles.
These hard containers, as represented by the PET bottles, are hardly reduced in their own capacities as their contents are reduced. Therefore, the hard containers are highly stationary as containers and can be used as pressure-resisting containers according to their shape. Thus, the hard containers offer a feature in that they can also be used as pressure-resisting containers for carbonated beverages or the like.
Like the glass bottles or the like, however, the hard containers such as the PET bottles will establish cavities as their contents are reduced, and the cavities will be occupied by air so that the contents are oxidized with the air. Therefore, the hard containers are not suited for storing the beverages effected by contact with the air, such as wine, sake, whiskey, fruit beverages, and vegetable juices.
On the other hand, the hard containers always have constant capacities so that they themselves always occupy a constant amount of space, no matter whether or not they have contents. It is easily understood how wasteful this is, if a case in which a container that is filled with a beverage is stored in a refrigerator is imagined. Where a 1 liter container containing 200 cc of water is stored in a refrigerator, a volume of 800 cc of the container occupies the refrigerator as wasted space.
With an increase in consciousness of environmental protection in recent years and, on the other hand, with a view towards getting rid of disposable containers, more inexpensive bag-shaped containers have been employed for rebottling, instead of the PET bottles, especially for home detergents. Most of the bag-shaped containers for these purposes are the self-standing containers called “stand pouches” because they are easily displayed at shops.
Thus, we had an idea that the stand pouch containers are used in placed of the PET bottles, and have made various investigations. We have found out to mount a pouring port in the stand pouch container and to attach a check valve to the pouring port. Then, this check valve is opened to allow the contents to migrate when subjected to a pressure in the direction to pour the contents and is closed when subjected to a pressure in the filling direction.
At this time, especially the upper portion of the inside of the self-standing container formed of a soft sheet is automatically subjected to a vacuum by the downward flow phenomenon due to the gravitational force of the contents. By this vacuum, moreover, the check valve is closed when the pressure is applied in the filling direction of the self-standing container (to suck the contents), so that the container can prevent the intake of air. In other words, this self-standing container can be said to be a so-called “vacuum container having a suction preventing function in the vacuum” for preventing the inflow of air at all times.
Here, it has been found that this self-standing container retains its self-standing property only while it is filled up with the contents. It has also been found that the container has its capacity reduced and loses its self-standing property as the content is reduced, and that a bag-shaped container 200 having lost its rigidity, as shown in FIG. 9, folds midway such that its head collapses, thereby raising a problem in that the bag-shaped container falls down and is hard to handle.
The present invention has an object to provide both the so-called “self-standing type bag-shaped vacuum container” capable of preventing the immigration of air at all times and a stand pouch type container which retains the advantage of flexibility and high capacity efficiency, as belonging to that of the prior art, and which has a self-standing property when the content is reduced as is absent in that of the prior art.
In the hard container of the prior art, such as a glass bottle or a PET bottle, on the other hand, the pouring rate could always be controlled to be constant by gripping the container firmly with the hands of a user and by controlling the tilting angle of the bottle.
Here, the hard container of the prior art is not or slightly deformed when gripped with the hands, and no internal pressure is established in the container so that the content is not vigorously discharged, but is poured out.
Recently, however, a bag-shaped container having a cylindrical pouring port has been used especially as a beverage container, The bag-shaped container is made flexible and foldable, and has its entire capacity reduced as the content is reduced. Therefore, this container is able to reduce the amount of waste by folding and disposing of it.
However, the soft container, such as the bag-shaped container described above, is flexible so that an internal pressure is easily established, when the container body is squeezed, to discharge the content vigorously. This characteristic is a defect intrinsic to a soft container body of the bag-shaped container or the like. Therefore, when the content is transferred from the bag-shaped container to another container, the content is poured not by squeezing the container body of the bag-shaped container, but by gripping and tilting the outer edge of the container body, by applying the pouring port to the inlet port of the container without spilling the transferred content, and by pushing the container body to pour the content. However, this handling is so troublesome that the content will be vigorously discharged, thereby causing a spill unless special care is taken. On the other hand, a fall has to be feared at all times so long as the soft container stands by itself.
Therefore, the present invention has been contemplated to solve the above-specified problems and has an object to provide a bag-shaped container which is freed from any vigorous discharge of the content even if its body is carelessly squeezed and which can take the place of the hard container of the prior art, such as the glass bottle or the PET bottle.